1. Technical Field of the Invention
The present invention relates to a reactor available for a power converter or the like.
2. Related Art
As a reactor for vehicles or a power converter like a DC-DC convertor, various types of structure are known, for example as described in Japanese Published Patent Application (JPA) 2010-199257. Afore mentioned reactor provides both a solenoid coil which generates a magnetic field by passing electricity through it and a core which consists of a non-conductive epoxy resin in which magnetic powder is included, wherein the coil is embedded within the core.
Especially in the reactor, a columnar member is disposed in a center of the core for improving radiation of heat generated by the coil and the core when electricity is passing through the coil.
In the reactor, the columnar center member is formed for example by die casting. However, mold lubricant such as silicon applied on the surface of a mold often remains behind on a surface of the columnar center member formed by the die casting.
Therefore in a case that the columnar center member is embedded in the core, adhesion between the columnar center member and the core is often insufficient since the congeniality between the mold lubricant such as silicone and non-conductive resin such as epoxy resin for core is insufficient.
If the adhesion between the columnar center member and the core is insufficient, it is feared that the efficiency of the radiating of heat toward the columnar center member from the core may become lowered.
Still more, in a reactor a large force of repulsion is generated between adjoining conductive wirings during operation. The coil may vibrate since the force of repulsion changes with the current flowing in the coil. This vibration travels to the core and the columnar center member so that the entire reactor vibrates.
Accordingly if the adhesion of the columnar center member to the core is not sufficient, there is a risk that the reactor's vibration may become larger caused by lowering of stiffness of the entire reactor. It is unacceptable.
Then, in the light of conditions set forth above, it is needed to provide a reactor such that the vibration of the entire reactor can be lowered and the efficiency of radiating heat generated by the coil and the core can be improved.